Appliance knobs



July 2, 1957 M. w. MARRAPl-: 2,797,591 v APPLIANCE xNoBs f Filed July1953 Igp. s. 'A 17332422 20 1731 I8 Il I 1y lel f 6 8 4' 'q Y J'll 7our@ 4% g )fm AITURNEKS APBLIANCE "KNOBAS Marius W. Marrapese, ledford,Ghio, assignor to 1`he Patent Button Company of Tennessee, Inc.,Knoxville, Tenn., a corporation of Tennessee Application July,21953Serial No. 366,140

8 laims. (Cl. 74-528) This application is a continuation-inpart of myprior application'for Appliance'lnobs, filed September 3, 1952, SerialNo. 307,617.

This invention relates to improvements in appliance knobs, and moreparticularly to the control knobs for gas and electric stoves and otherappliances. Itis well known that young children tend to turn on electricand lgas appliances, which often create real hazards and sometimesserious .injury. Various attempts have been proposed heretofore toprovide knobs which will prevent accidental operation of suchappliances, or manipulation thereof by small children, but these havedepended on threaded connections between the parts, orwotherobjectionable characteristics thereof, which have not been satisfactoryfor efficient manufacture and use.

A valve knob generally requires lat least one indication point to showthe dierent set positions of the valve or other 'control for theappliance, as the Off position. In some instances, additional legendsare desirable thereon, as"O`n, Broih Simmen etc. Such markings mustnecessarily rotate with the turning of rthe valve stem or control forthe appliance.

ln my prior application, such legends were applied to the surroundingrim of the back plate, which required an outward projection thereofbeyond the rotatable knob. yIt has been found that such a projectionleaves that portion exposed to the possibility of its being gripped forturning the valve or appliance control, whereby that particularconstruction may not be considered as completely foolproof as isdesired.

One object of this invention is to overcome the objections heretoforeencountered in prior constructions, including the form of knob set forthin my above-mentioned application, and to improve the constructionthereof for controlling various appliances.

Another object of the invention is to provide a surface which is fixedto the appliance control member upon which an indication may be appliedand which cannot be grasped for turning of the appliance control exceptby manipulation of the control knob.

These objects may be accomplished, according to one embodiment of theinvention, by confining the back plate of the center post within theouter periphery of the shell of the control knob so as not to leave itexposed for grasping by children or anyone else who may try to turn theappliance control, without the necessity for manipulation and engagementof the control knob. The center post is adapted to be xed to theappliance control unit, such as the valve stem of a gas appliance. Adisk is xed to the center post to rotate therewith upon turning of thepost, and carries the indicia that indicates the rotated position of theappliance conrol, such as the valve stern. This disk is confined withinan axially projecting portion of the outer shell of the control knob, sothat it cannot be grasped by a child, for instance, for rotating thecontrol member. Thus, a completely foolproof appliance Patented July 2,1957 ice knob is provided ,withoutprojectingparts of :the appliancecontrol forrotating thelatter withoutmanipulationtofthe controlknobnto'itsengaged position. Thelatter normally is `disengaged by springmeans and has suitable clutch meansfor ,engagementfthereoi as set forthmorein detailin my above-mentioned application.

One embodiment-of Vthis invention isillustrated in the Laccompanyingdrawings, in which:

Fig. `l is a Iperspective view of the appliance knob detached;

IFig. 2 is a perspective view of the center post and back Plate;

Fig. 3 is a cross section through the appliance knob, with the controlknobinits disengaged position.

4 is a similarview showing the control knob engaged; and

Fig. 5 is a detail plan view of the center portion of the appliance knobwith parts removed.

This appliance knob maybe used for controlling Vthe valve of a gas stoveor the electric switch of an electric stove, or other electriclappliance that will prevent operation of the valve or switch by youngchildren, or accidental or unintended operation thereof by bodilycontact with the Valve orswitch. I have designated a portion oftheappliance control, either a valve stem or an electric switch shaft,generally by the numeral l, and it will be understood that this isintended merely as an example of thecontrol-,means for the appliance towhich the invention may be applied.

The appliance knob includes a center port generally designated at 2,'which is tubular and has a suitable provision for connection with theshaft 1, such as a split D-shaftthat will provide a press-tit or otherconnection between the post 2 land the shaft 1 or other .control means.The post 2 ,is `partially lClosed at its upper end by an inturned flange3, provided with a central hole 4 therein, as shown in'Figs. 2 and 3.The holed, through the closed end portion 3 .of the center post, may beprovided with a rcounterbore 5,;as shown, to receive the head of afastening that extends through the central hole 4, as hereinafterdescribed.

At its lowerend,.the center post 2 is provided with a back plate 6,which projects outwardly therefrom in a radial direction, and preferablyis formed in one integral piece with the center post Z.

Acontrol knob is provided on the post 2 and comprises an outer shellgenerally indicated at 7, which is somewhat cylindrical in form but mayhave peripheral ribs 8 thereon to facilitate grasping of the shell, orother suitable means that will provide a friction surface thereon tofacilitate rotation of the control knob by hand. The outer shell 7 isshown as having a depending skirt portion at its lower edge, asindicated at 9, that extends to the lower face of the back plate 6, andencloses the latter completely, thus confining the back plate at itsperiphery againset accidental grasping by a child who might try to turnthe appliance control thereby.

The control knob has a hub lll vofcylindrical form surrounding the post2 and journaled thereon for rotation and' axial sliding movementrelative thereto. The hub 10 is spaced radiallyrfrom the outer shell 7and is connected therewith by a radially extending rib 11 that extendscircumferentially around the hub vl() therebetween. The` web llis ofrset axially of the outer shell 7 with a portion of the web spaced fromthehub 1t) to provide a circumferential channel 12 therearound, forminga lspring seat in the underside of the control knob.

Provision is made for clutchv connection between 4the control knob 7,-11and `the hub. 2 upon axial Yshifting of the control` knob relativeAthereto to engage the clutch mepans,.-while.permitting free turningmovement of the control knob relative to the center post upondisengagement of the clutch means. Several forms of clutch engagementmeans are shown in my application referred to above, any of which may beused, as desired, for this purpose. However, I have illustrated in thisembodiment a clutch connection provided with interengaged teeth 13 and14 formed, respectively, on the outer edge portion of the back plate 6and on the otfset portion of the web 11 just inside the outer shell 7.These teeth are formed in respective rows, spaced apartcircumferentially in each row, and so disposed as to interengage witheach other 'to form a positive jaw clutch upon inward movement of thecontrol knob relative to the post 2.

Yieldable means should be provided for normally maintaining the controlknob in its outer position with the clutch means disengaged, except whenit is desired to positively turn the appliance control. I have shown acoiled compression spring interposed between the back plate 6 and theweb 11, surrounding the hub 10 and seated within the recess 12 of thecontrol knob. This spring 15 normally will disengage the clutch teeth13-14 when the control knob is released, and yet will permit engagementthereof uponaxial shifting of the control knob relative to the centerpost 2.

The outer end portions of the center post 2 and hub 10 are overlapped bya Washer 16 which is seated upon the outer end of the post 2 andcentered by projecting `pins 17 on the post, preferably formed integraltherewith, The washer 16 thus 30 as illustrated in this embodiment.limits the outward sliding movement of the control knob 7-11 axiallyalong the center post 2 under the influence of the spring 15. v

The washer 16 is retained inplace by a central disk, generally indicatedat 18. The disk 18 extends over the outer face of the center post 2 andthe control knob throughout the major portion of the area thereof withan `inturned peripheral flange 19 that is spaced from the surroundingwall formed by the outer shell 7, so as to allow freedom of rotaryandaxial movement of the control knob relative to the central disk 18,and yet closing the outer end of the control knob by said central disk.The central disk 18 has a corrugation 20 formed ltherein at the outerend of the post 2, providing an edge portion 21 that bears upon theperiphery of the washer 16 to reduce the area of contact therewith, andyet to vconfine the washer in place on the post 2. The central disk 18also has inturned ears 22 on opposite sides of its center, beside theaxially projecting pins 17 on the post 2 to center the disk 18 withrespect thereto.

The central disk 18 is confined by a rivet or other fsuitable fastening,generally indicated at 23, having a head 24 overlying the outer face ofthe central disk 18 at the center thereof, while a head 25 on the rivet23 engages the countersunk portion 5 of the centerbore of the post 2 toconfine the parts in secure relation thereto without the use of screwmeans.

Provision is made for holding the central disk 18 against rotationrelative to the center post 2 and to cause it to rotate therewith. Inthis embodiment of the invention, the washer 16 is provided with anelongated slot l28, as shown in Fig. 5, through the opposite ends ofwhich the pins 17 project. The ears 22 on the central Vdisk 18 are alsoturned downinto the opposite ends of nthe slotr28 beside the pins 17,while the center of this slot 28 is enlarged to accommodate therivet-23. The projecting pin .17 and ears 22 act as keys to the washer16, while the latter connects the central disk 18 with the center post 2through these key connections, thereby eliminating any independentturning of the washer `16 on the central disk 18vwith respect to thecenter post 2; The central disk 18 also serves to carry suitable indiciathereon, as generally indicated at 26,tbeing illustrated by 'the wordfOff. Any other suitable indicia maybe used Cthereon such, for instance,as On, Broil, Simmer,n

nknob and post engageable upon rearward movement of 1f" withoutmanipulating the control knob, which normally is disengaged by thespring 15, thus providing an effective foolproof control. As notedabove, the disk which carries the indicia or legend is recessed withinthe free r rotatable outer shell and confined entirely by the sur- 0rounding wall thereof, when the control knob is in its outermostposition, which prevents grasping of this disk by hand.

The center post and control knob may be molded of plastic or otherwiseconstructed of suitable material.

This construction also eliminates the requirement of lappliance knobsproposed heretofore which used threaded connections between the parts.Thus, a practical unitary Ystructure is provided, with the part fullyenclosed and r.without danger of disconnection as a result of suchthreaded connections, as were required therein. An ef vfective appliancecontrol which is completely foolproof is thus provided.

While the invention has been illustrated and described in oneembodiment, it is recognized that variations and 'changes may be madetherein without departing from `the invention as set forth in theclaims.

I claim:

l. An appliance knob comprising a center post adapted A to be connectedwith an appliance control member, a control knob mounted on the centerpost for rotary and 'axial movement relative thereto, clutch meansbetween the knob and post engageable upon rearward movement of said knoband a disk carried by the center post and fixed 40 thereto andsubstantially covering but received in the front the knob and postengageable upon rearward movement of said knob and a disk carried by thecenter post and fixed thereto and substantially covering the outerportion of the knob, means yieldably urging control knob outwardlyrelnative to the center post, said control knob having an outer 'rimportion surrounding the disk. 3. An appliance knob comprising a centerpost adapted to be connected with an appliance control member, a controlknob mounted on the center post for rotary and axial movement relativethereto, clutch means between the said knob and a disk carried by thecenter post and fixed thereto and substantially covering the front ofthe knob, and means yieldably urging the control knob to an outerposition relative to the center post, said control knob having an outerrim portion therein with the periphery of the disk inwardly of the outeredge of said rim portion in said outer position.

4. An appliance knob comprising a center post adapted to receive thereinan appliance control member, a control knob mounted on the center postfor rotary and axial movement relative thereto, said knob having anouter recess providing an internal hub wall portion and a spaced Yexternal rim wall portion, means yieldably urging the control knoboutwardly relative to the center post, a member carried by the centerpost and fixed thereto, overlapping and providing a lstop for the hubwall portion, and a disk I overlapping the center post and extendingbetween the rim portion of the knob and the member.

5. An appliance knob comprising a center post adapted to be connectedwith an appliance control member, a control knob mounted on the centerpost for rotary and axial movement relative thereto, clutch meansbetween the knob and post engalgeable upon rearward movement of saidknob, said control knob having a hub portion journaled on the centerpost and having an annular recess therein surrounding the hub portion,and a coiled spring surrounding the center post and having one en'dseated in said recess, saitl control knob having an outer shell spacedfrom the hub portion with a radial web therebetween having the annularrecess formed in said web.

6. An appliance knob comprising a center post a'dapted to be connectedwith an appliance control member, a control knob mounted on the centerpost for rotary and axial movement relative thereto, means forming aclutch connection ltherebetween the control knob and the center post forengagement upon axial movement of the control knob in one directionrelative thereto, a central disk covering the outer end portion of thecontrol knob and having indicia thereon to represent a position of thecenter post, and means `forming a key connection between the center postand the central disk locking these parts together.

7. An appliance knob comprising a center post adapted to be connectedwith an appliance control member, a control knob mounted on the centerpost for rotary and axial movement relative thereto, meansv forming aclutch connection between the control knob and the lcenter post forengagement upon axial movement of the control knob in one directionrelative thereto, a central disk covering the outer end portion of thecontrol knob and having indicia thereon to represent a position of thecenter post, a washer overlapping adjacent portions of the control knoband center post and having an elongated slot therein, key means iixed tothe center post and projecting into the slot, said central diskoverlapping the washer, and key means connected with the central ydiskand projecting into the slot beside the first-mentioned key means andcooperating therewith to form a locked vconnection between the centraldisk and the center post for maintaining these parts in secure relationto each other.

8. An appliance knob comprising a center post adapted to be connectedwith an appliance control member, a control knob mounted on the centerpost for rotary and axial movement relative thereto, clutch meansbetween the knob and post engageable upon rearward movement of saidknob, a disk carried by the center post and fixed thereto andsubstantially covering, but received in, the front of the knob, said-post having a back plate at the rear end thereof, said knob having arearwardly projecting rim at the rear end thereof enclosing the adjacentperiphery of the back plate.

References Cited in the file of this patent UNITED STATES PATENTS409,100 Hall Aug. 13, 1889 600,849 Brown .Man 15, 1898 893,184 MercerJuly 14, 1908 1,100,286 Cornelius June 16, 1914 1,113,613 Goozey Oct.13, 1914 1,527,617 Tuska Feb. 24, 1925 1,575,410 Bradley Mar. 2, 19262,262,667 Datorn et al Nov. 11, 1941 2,427,310 Shumaker Sept. 9, 19472,501,008 Schramm Mar. 21, 1950 2,602,351 Ringler et al. July 8, 19522,660,904 Hilsinger Dec. 1, 1953 FOREIGN PATENTS 14,680 Great BritainJuly 17, 1899

